载铁活性炭吸附材料的制备及对水中砷（Ⅴ）的吸附研究

发布时间：2018-06-14 10:30

  本文选题：载铁活性炭 + 制备　； 参考：《江西理工大学》2015年硕士论文

【摘要】：砷是剧毒元素,可对人、动植物造成伤害。水体砷污染已成为一突出问题。立足于环境材料的研发和应用,本文采用高温蒸发法和恒温浸润法改性颗粒活性炭,并改变两种方法中的制备条件、修饰物质制备不同的载铁活性炭吸附剂,选取最佳吸附剂进行吸附性能研究并对其进行EDS、SEM、XRD、XPS、FTIR等表征,同时对两类材料吸附砷的铁效率和稳定性进行对比研究。研究结果表明,高温蒸发法的最佳吸附剂是采用2 g Fe SO4·7H2O,添加5 m L H2O2,高温蒸发15min制备,命名为Fe(1.39%)-15 min-H2O2,1.39%为铁含量;恒温浸润法的最佳吸附剂是采用2 g Fe SO4·7H2O,添加10 m L H2O2,在温度100℃下浸润24 h制备,命名为Fe(0.485%)-24 h-H2O2.Fe(1.39%)-15 min-H2O2对砷的最大吸附容量是2.551 mg/g,而Fe(0.485%)-24h-H2O2的吸附容量随初始浓度增大而增大;两种材料的吸附容量均随温度升高而降低;Fe(1.39%)-15 min-H2O2和Fe(0.485%)-24 h-H2O2吸附砷的平衡时间分别是24 h、30h;Fe(1.39%)-15 min-H2O2在p H(4~8)内稳定性和去除效果都很好,而Fe(0.485%)-24 h-H2O2在p H(2~10)内去除效果好,但在p H4时,其稳定性差。Cl O4-、SO42-、PO43-、Mg2+对Fe(1.39%)-15 min-H2O2吸附砷有抑制作用,而Ca2+对其吸附起促进作用;SO42-、NO3-、Cl O4-、PO43-对Fe(0.485%)-24 h-H2O2吸附砷有抑制作用,而Cl-(100 mg/L)、Br O3-、Ca2+、Mg2+对其吸附起促进作用。Fe(1.39%)-15 min-H2O2对砷的吸附过程更适合用Frundlich模型来描述,而Fe(0.485%)-24 h-H2O2更适合用Linear模型;这两种材料的吸附反应都主要是物理吸附,且均是自发的放热熵减反应;准二级动力学模型均可以很好的描述这两种材料对砷的吸附,且它们的反应速率控制阶段是外扩散阶段;两种材料的解吸率均大于80%。由EDS可知,Fe(1.39%)-15 min-H2O2的Fe原子百分比高于Fe(0.485%)-24 h-H2O2;SEM显示Fe(0.485%)-24 h-H2O2表面覆盖厚而均匀的纳米羟基铁,Fe(1.39%)-15 min-H2O2表面覆盖薄而均匀烧结扭曲的羟基铁;由FTIR、XRD、XPS可知,两种材料表面均存在无定型的Fe OHSO4和Fe OOH,并且它们表面还存在二价铁;恒温浸润法所制备的吸附剂铁效率远远高于高温蒸发法;Fe(0.485%)-24 h-H2O2的稳定性优于Fe(1.39%)-15 min-H2O2,表明制备方法对铁效率、稳定性有重要的影响。
[Abstract]:Arsenic is a highly toxic element that can cause harm to humans, animals and plants. Water arsenic pollution has become a prominent problem. Based on the research and application of environmental materials, the granular activated carbon was modified by high temperature evaporation method and constant temperature soaking method, and the preparation conditions of the two methods were changed to prepare different adsorbents of iron loaded activated carbon. The optimum adsorbents were selected to study the adsorption properties and the results were characterized by EDSSEMX RDX XPS FT-IR. The iron efficiency and stability of the two kinds of materials on arsenic adsorption were compared. The results show that the best adsorbent for high temperature evaporation method is 2 g FeSO 4 7H 2O, adding 5 mL H 2O 2 and evaporating 15min at high temperature, named Fe 1. 39% -15 min H 2O 2 H 2O 2 1.39% iron content. The best adsorbent for isothermal soaking method is 2 g FeSO 4 7H 2O and 10 mL H 2O 2 at 100 鈩，

本文编号：2017079